The present invention relates to a gauge for enabling an electrician or lineman to determine correct connector size for a particular conductor.
Connectors, particularly compression connectors are designed for reliable and repeatable electrical connections, capable of withstanding a wide range of electrical and environmental conditions. Connectors are fabricated of copper for use on copper conductors and aluminum for aluminum conductors with the connectors being designed for attachment to the conductor by means of a circumferential crimp or by an indent crimp.
The desired result in each type crimp is an electrical connection with the conductor cable strands in intimate contact with each other and with the connector barrel with virtually no air pockets and with high pull out strength.
In current practice there is a common problem of determining proper connector size to accommodate the flexible conductors, i.e., a cable of multiple strands commonly used for motor leads. These flexible conductors are extremely difficult to identify by size. After the insulation is stripped away allowing access to the end of the conductor, with appropriate care having been taken not to splay the cable strands, the conductor end is out-of-round as a result of stripping especially in the case of soft conductors, or the conductor is forced out-of-round by use of a measuring caliper. Nonetheless, the only way the installer can be assured of achieving a UL-listed reliable connection is to follow the connector manufacturer's installation instructions calling for the closest fitting connector which can be fitted over the conductor.
Heretofore, the only way to be absolutely sure about connector selection has been to follow this procedure:
1. Measure the diameter of one strand of the conductor to the nearest 1/1000th of an inch using a micrometer caliper.
2. Count the strands.
3. Consult the connector manufacturer's catalog for specific connector recommendation.
This procedure is tedious, time consuming and difficult to perform accurately and seldom used in practice. As a result, connectors are chosen with far less precision and errors are often made. For example, connectors that are too tight cause strand fraying and extra strands are trimmed off. Connectors that are too loose accommodate the conductor easily, however, when installed using the crimping tool recommended by the manufacturer the connector is undercompressed with respect to the conductor resulting in a loose connection prone to overheating and failure and not up to UL standards.
There remains a need for a device that enables installers to achieve quick and accurate matching of connectors and conductors.